1,720,963 research outputs found
Ribonuclease A can be transformed into a dimeric ribonuclease with antitumor activity.
No full textA cDNA coding for bovine pancreatic RNase A was mutagenized to insert a proline, leucine, and 2 cysteine residues, i.e. the residues present at corresponding positions in the subunit of seminal RNaset, he only dimeric RNase of the pancreatic-type superfamily. The mutant, expressed in Escherichia coli, eventually aggregated into catalytically active dimers. Like naturally dimeric
seminal RNase, at equilibrium the mutant dimeric RNase A adopted two quaternary structures (one with an exchange of the N-terminal segments between partner subunitst, he other with no exchange) and displayed a selective toxicity for malignant cells, absent in the
monomeric, parent protein
The determinant of the dimeric structure of seminal ribonuclease are located in its N-terminal region.
No full textHints on the evolutionary design of a dimeric RNase with special bioactions.
No full textResidues P19, L28, C31, and C32 have been implicated with key
roles in determining the dimeric structure and the N-terminal domain swapping of seminal RNase. In an attempt to have a clearer understanding of the structural and functional significance of these residues in seminal RNase, a series of mutants of pancreatic RNasAe was constructed in which one or more of the four residues were introduced into RNase A. The RNase mutantsw ere examined for: (1) the ability to form dimers;( 2) the capacity to exchange their N-terminal domains; (3) resistance to selective cleavage by subtilisin; and (4) antitumor activity.
The experiments demonstrated that: (1) the presence of intersubunit disulfides is both necessary and sufficient for engenderinga stably dimeric RNase;( 2) all four residues play a role in determining the exchangeo of N-teminal domains; (3) the exchange is the molecular basis for the RNase antitumor action; and (4) this exchange is not a prerequisite in an evolutionary mechanism for the generation of dimeric RNases
The determinant of the dimeric structure of seminal ribonuclease are located in its N-terminal region.
No full textEngineering of Bovine Seminal Ribonuclease: expression of the secreted recombinant protein.
No full text
- …
